At a press conference on Wednesday, Mr Morrison was asked whether a lockdown would be a good idea.

"You're suggesting I should close down businesses where there's no medical advice that they should," he replied.

"I don't understand why we would cause that harm to a business and all their workers and their livelihoods for the sake of some sort of message convenience.

"I think that would be quite reckless."

Prime Minister Scott Morrison said he would not close more businesses unless the AHPPC advises National Cabinet that it is necessary.

The Prime Minister said they were seeking to impose social distancing measures for the community "on a scalable basis".

"Our advice is not to extend that more broadly within the retail sector," Mr Morrison said.

"People can still go to car yards, they can still do those things, where it's necessary for them to do that, and those businesses are expected to put in place the arrangements … which is the four square metres per person, how many people can be in that premise.

"We are not going to do things to a business or someone's job and livelihood where at this stage that may, and is, not necessary."

Appearing on ABC this morning, newly appointed Deputy Chief Medical Officer Dr Nick Coatsworth said their approach had been "hard and fast".

"To say that we've gone light and slow would be completely inaccurate," he said.

"The measures that we've got in at the moment are unprecedented. The impact they're going to have on individual families is unprecedented."

Advice remains to stay home when possible - if you must go out for essentials or healthcare please stay away from other people and wash your hands regularly. If you are sick you MUST NOT leave home for any reason. Call your doctor. https://t.co/O8401hxOqxpic.twitter.com/KTydn685hw

— Australian Government Department of Health (@healthgovau) March 25, 2020

Dr Coatsworth said it's all a matter of degrees.

"And I have to say that the experts around the table of the Australian Health Protection Principal Committee do not think that this will be over in weeks, if you put in harder and faster measures," he said.

The AHPPC, which guides the emergency medical decisions of National Cabinet, is comprised of all state and territory Chief Health Officers and chaired by Australia's Chief Medical Officer, Professor Brendan Murphy.